diff options
Diffstat (limited to 'backport/compat/backport-4.0.c')
| -rw-r--r-- | backport/compat/backport-4.0.c | 179 |
1 files changed, 0 insertions, 179 deletions
diff --git a/backport/compat/backport-4.0.c b/backport/compat/backport-4.0.c index eb950826..84a4c6bf 100644 --- a/backport/compat/backport-4.0.c +++ b/backport/compat/backport-4.0.c @@ -15,187 +15,8 @@ #include <linux/printk.h> #include <linux/export.h> #include <linux/trace_seq.h> -#include <linux/ftrace_event.h> #include <asm/unaligned.h> -static __always_inline long __get_user_pages_locked(struct task_struct *tsk, - struct mm_struct *mm, - unsigned long start, - unsigned long nr_pages, - int write, int force, - struct page **pages, - struct vm_area_struct **vmas, - int *locked, bool notify_drop, - unsigned int flags) -{ - long ret, pages_done; - bool lock_dropped; - - if (locked) { - /* if VM_FAULT_RETRY can be returned, vmas become invalid */ - BUG_ON(vmas); - /* check caller initialized locked */ - BUG_ON(*locked != 1); - } - - if (pages) - flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; - - pages_done = 0; - lock_dropped = false; - for (;;) { - ret = __get_user_pages(tsk, mm, start, nr_pages, flags, pages, - vmas, locked); - if (!locked) - /* VM_FAULT_RETRY couldn't trigger, bypass */ - return ret; - - /* VM_FAULT_RETRY cannot return errors */ - if (!*locked) { - BUG_ON(ret < 0); - BUG_ON(ret >= nr_pages); - } - - if (!pages) - /* If it's a prefault don't insist harder */ - return ret; - - if (ret > 0) { - nr_pages -= ret; - pages_done += ret; - if (!nr_pages) - break; - } - if (*locked) { - /* VM_FAULT_RETRY didn't trigger */ - if (!pages_done) - pages_done = ret; - break; - } - /* VM_FAULT_RETRY triggered, so seek to the faulting offset */ - pages += ret; - start += ret << PAGE_SHIFT; - - /* - * Repeat on the address that fired VM_FAULT_RETRY - * without FAULT_FLAG_ALLOW_RETRY but with - * FAULT_FLAG_TRIED. - */ - *locked = 1; - lock_dropped = true; - down_read(&mm->mmap_sem); - ret = __get_user_pages(tsk, mm, start, 1, flags | FOLL_TRIED, - pages, NULL, NULL); - if (ret != 1) { - BUG_ON(ret > 1); - if (!pages_done) - pages_done = ret; - break; - } - nr_pages--; - pages_done++; - if (!nr_pages) - break; - pages++; - start += PAGE_SIZE; - } - if (notify_drop && lock_dropped && *locked) { - /* - * We must let the caller know we temporarily dropped the lock - * and so the critical section protected by it was lost. - */ - up_read(&mm->mmap_sem); - *locked = 0; - } - return pages_done; -} - -/* - * We can leverage the VM_FAULT_RETRY functionality in the page fault - * paths better by using either get_user_pages_locked() or - * get_user_pages_unlocked(). - * - * get_user_pages_locked() is suitable to replace the form: - * - * down_read(&mm->mmap_sem); - * do_something() - * get_user_pages(tsk, mm, ..., pages, NULL); - * up_read(&mm->mmap_sem); - * - * to: - * - * int locked = 1; - * down_read(&mm->mmap_sem); - * do_something() - * get_user_pages_locked(tsk, mm, ..., pages, &locked); - * if (locked) - * up_read(&mm->mmap_sem); - */ -long get_user_pages_locked(unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, - int *locked) -{ - return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); -} -EXPORT_SYMBOL_GPL(get_user_pages_locked); - -/* - * Same as get_user_pages_unlocked(...., FOLL_TOUCH) but it allows to - * pass additional gup_flags as last parameter (like FOLL_HWPOISON). - * - * NOTE: here FOLL_TOUCH is not set implicitly and must be set by the - * caller if required (just like with __get_user_pages). "FOLL_GET", - * "FOLL_WRITE" and "FOLL_FORCE" are set implicitly as needed - * according to the parameters "pages", "write", "force" - * respectively. - */ -static __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, - unsigned int gup_flags) -{ - long ret; - int locked = 1; - down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); - if (locked) - up_read(&mm->mmap_sem); - return ret; -} - -/* - * get_user_pages_unlocked() is suitable to replace the form: - * - * down_read(&mm->mmap_sem); - * get_user_pages(tsk, mm, ..., pages, NULL); - * up_read(&mm->mmap_sem); - * - * with: - * - * get_user_pages_unlocked(tsk, mm, ..., pages); - * - * It is functionally equivalent to get_user_pages_fast so - * get_user_pages_fast should be used instead, if the two parameters - * "tsk" and "mm" are respectively equal to current and current->mm, - * or if "force" shall be set to 1 (get_user_pages_fast misses the - * "force" parameter). - */ -long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages) -{ - return __get_user_pages_unlocked(current, current->mm, start, nr_pages, - write, force, pages, FOLL_TOUCH); -} -EXPORT_SYMBOL_GPL(get_user_pages_unlocked); - - /** * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory * @buf: data blob to dump |